Fatty acid composition of frequently consumed foods in Turkey with special emphasis on trans fatty acids

Fatty acid compositions of frequently consumed foods in Turkey were analyzed by capillary gas chromatography with particular emphasis on trans fatty acids. The survey was carried out on 134 samples that were categorized as meat products, chocolates, bakery products and others. The meat products except chicken-based foods have trans fatty acids, arising as a result of ruminant activity, with an average content of 1.45 g/100 g fatty acids. The conjugated linoleic acid content of meat and chicken doner kebabs were found higher than other meat products. Chocolate samples contained trans fatty acids less than 0.17 g/100 g fatty acids, with the exceptional national product of chocolate bars and hazelnut cocoa cream (2.03 and 3.68 g/100 g fatty acids, respectively). Bakery products have the highest trans fatty acid contents and ranged from 0.99 to 17.77 g/100 g fatty acids. The average trans fatty acid contents of infant formula and ice-cream, which are milk-based products, were 0.79 and 1.50 g/100 g fatty acids, respectively. Among the analyzed foods, it was found that coffee whitener and powdered whipped topping had the highest saturated fatty acid contents, with an average content of 98.71 g/100 g fatty acids.     

A method for assessing dietary intakes of n-3 long-chain polyunsaturated fatty acids and trans fatty acids in an Irish adult population

Abstract

The present study aimed to quantify dietary intakes of eicosapentaenoic acid (EPA), docosahexaenoic acid (DHA) and trans fatty acids (trans FA) in Irish adults using the North/South Ireland Food Consumption Survey (NSIFCS). To update the NSIFCS database, specific approaches were necessary to select accurate data. Published references were the main data source used to update for EPA and DHA (21.7%), while the UK Nutrient Databank was most frequently used to update for trans FA (46.7%). Total EPA and DHA mean daily intake was 275 mg/day whilst trans FA mean daily intake was 0.72% food energy. Younger adults had significantly lower intakes of EPA and DHA than older adults. The present study shows that dietary EPA and DHA intakes in the Irish adult population are below recommendations, especially among the younger population. Conversely, trans FA intakes are within the recommended value of < 2% food energy.     

Translating research into action: a case study on trans fatty acid research and nutrition policy in Costa Rica

Mounting epidemiologic evidence worldwide has fostered policy regulation of industrially made trans fatty acids (TFA) in several developed countries. Despite country-specific evidence about the effects of TFA on cardiovascular disease in Costa Rica, policy regulation has yet to occur. This qualitative study uses a conceptual framework to identify factors that may impede or promote the process of translation of scientific evidence about TFA into policy in the specific context of Costa Rica. We used single case-study methodology to integrate two sources of data: review of relevant internal documents and in-depth, semi-structured interviews with 21 respondents purposively sampled from three sectors: the cooking oil and food industries, research and academia, and government entities. Content analysis, guided by a conceptual framework of research utilization, revealed 68 emergent themes divided across four categories of analysis. In brief, study participants perceived the political context suitable for discussing policies related to healthy fats. Nevertheless, TFA regulation was not part of the Costa Rican political agenda. Barriers perceived by respondents that impede knowledge translation included: (1) lack of awareness of in-country scientific studies on health effects of TFA; (2) lack of consensus or information about policy options (nutrition labelling, dietary guidelines, legislative mandates); (3) perceived distrust and disparate attitudes between sectors, believed by study participants to result in (4) limited collaboration across sectors. Commissioned task forces and other mechanisms to foster research engagement and facilitate sustained interaction and systematic collaboration among government, food industry and researcher sectors appear crucial in the consideration and adoption of nutrition policy in Costa Rica and other emerging economies.     

食品中反式脂肪酸使用现状及检测方法研究

食品中反式脂肪酸对人体健康的影响逐渐引起世界各国政府及社会的关注.我国政府也正在对食品中反式脂肪酸进行风险评估.本文阐述了反式脂肪酸的发展历程以及当前主要检测方法研究进展.     

Formation of trans fatty acids during the frying of chicken fillet in corn oil

To assess effects of heated edible oils on intake of trans fatty acids (TFAs); the formation of TFAs in cooking conditions was investigated by a frying system model, in which chicken fillet was fried in a commercial corn oil at 170?°C, for 12 frying cycles. The main TFAs detected in chicken fillet were trans C18:2 fatty acids (FAs) and trans C18:3 FAs, which exhibited no significant differences among the frying cycles. Besides, the content of trans C18:1 FAs were very low in all samples on different frying cycles. The intake of TFAs was estimated to be 0.06?g/100?g when chicken fillet fried in this process was consumed. These results suggest that an ordinary frying process upon a commercial corn oil has little impact on the daily TFAs intake.     

Dietary polyunsaturated fatty acid intake during late pregnancy affects fatty acid composition of mature breast milk

ObjectiveThe aim of this study was to investigate how maternal polyunsaturated fatty acid intake at different periods during pregnancy affects the composition of polyunsaturated fatty acids in mature human milk.MethodsA prospective study was conducted involving 45 pregnant women, aged between 18 and 35 y, who had full-term pregnancies and practiced exclusive or predominant breast-feeding. Mature breast milk samples were collected after the 5th postpartum week by manual expression; fatty acid composition was determined by gas chromatography. Fatty acid intake during pregnancy and puerperium was estimated through multiple 24-h dietary recalls. Linear regression models, adjusted by postpartum body mass index and deattenuated, were used to determine associations between estimated fatty acids in maternal diet during each trimester of pregnancy and fatty acid content in mature human milk.ResultsA positive association was identified between maternal intake of eicosapentaenoic acid (β, 1.873; 95% confidence interval [CI], 0.545, 3.203) and docosahexaenoic acid (β, 0.464; 95% CI, 0.212–0.714) during the third trimester of pregnancy, as well as the maternal dietary ω-3 to ω-6 ratio (β, 0.093; 95% CI, 0.016–0.170) during the second and third trimesters and postpartum period, with these fatty acids content in mature breast milk.ConclusionsThe maternal dietary docosahexaenoic acid and eicosapentaenoic acid content during late pregnancy may affect the fatty acid composition of mature breast milk. Additionally, the maternal dietary intake of ω-3 to ω-6 fatty acid ratio, during late pregnancy and the postpartum period, can affect the polyunsaturated fatty acid composition of breast milk.     

北京和广州市3岁以上人群反式脂肪酸食物消费状况调查分析

目的调查北京和广州两市3岁以上不同人群反式脂肪酸的摄入量以确定反式脂肪酸的高暴露食物以及高暴露人群。方法采用食物频率法调查过去3个月内被调查对象摄入各类含反式脂肪酸的食物的摄入频率以及平均每次的摄入量。结果两市的高暴露食物居第一位的均为植物油,其他食物顺位有所差异。共同的高暴露人群为13～17岁的年龄段人群和在校学生职业人群。结论两市反式脂肪酸高暴露食物与人群有所差异,其原因多样,有待进一步研究。     

N-3 fatty acids reduced trans fatty acids retention and increased docosahexaenoic acid levels in the brain

Introduction: The levels of docosahexaenoic acid (DHA, 22:6n-3) and arachidonic acid (AA, 20:4n-6) are critical for the normal structure and function of the brain. Trans fatty acids (TFA) and the source of the dietary fatty acids (FA) interfere with long-chain polyunsaturated fatty acids (LC-PUFA) biosynthesis.

Objectives: The aim of this study was to investigate the effect of TFA supplementation in diets containing different proportions of n-9, n-6, and n-3 FA on the brain FA profile, including the retention of TFA, LC-PUFA levels, and n-6/n-3 PUFA ratios. These parameters were also investigated in the liver, considering that LC-PUFA are mainly bioconverted from their dietary precursors in this tissue and transported by serum to the brain. Also, stearoyl-CoA desaturase-1 (SCD1) and sterol regulatory element-binding protein-1c (SREBP-1c) gene expressions were evaluated.

Methods: Male CF1 mice were fed (16 weeks) diets containing different oils (olive, corn, and rapeseed) with distinct proportions of n-9, n-6, and n-3 FA (55.2/17.2/0.7, 32.0/51.3/0.9, and 61.1/18.4/8.6), respectively, substituted or not with 0.75% of TFA. FA composition of the brain, liver, and serum was assessed by gas chromatography.

Results: TFA were incorporated into, and therefore retained in the brain, liver, and serum. However, the magnitude of retention was dependent on the tissue and type of isomer. In the brain, total TFA retention was lower than 1% in all diets.

Discussion: Dietary n-3 PUFA decreased TFA retention and increased DHA accretion in the brain. The results underscore the importance of the type of dietary FA on the retention of TFA in the brain and also on the changes of the FA profile.     

The health effects of dietary unsaturated fatty acids

• 2.1 The chemistry of fatty acids
• 2.2 Digestion, absorption and metabolism
• 2.3 Functions of unsaturated fatty acids

3 Unsaturated fatty acids in the UK diet

• 3.1 Sources of fat in the diet
• 3.2 Dietary recommendations for fat
• 3.3 Intakes of unsaturated fatty acids
• 3.4 Major contributors to unsaturated fatty acid intake
• 3.5 Trends in intake

4 Unsaturated fatty acids in health and disease

• 4.1 Unsaturated fatty acids and cardiovascular disease
• 4.2 Unsaturated fatty acids and diabetes
• 4.3 Unsaturated fatty acids and cancer
• 4.4 Unsaturated fatty acids and inflammatory conditions
• 4.5 Unsaturated fatty acids in fetal and infant development
• 4.6 Unsaturated fatty acids and cognitive function and behaviour
• 4.7 Emerging aspects of unsaturated fatty acids and health

5 Unsaturated fatty acids and public health

• 5.1 Labelling of unsaturated fatty acids
• 5.2 Are current UK recommendations adequate?
• 5.3 Opportunities to increase intake of long chain n‐3 PUFAs
• 5.4 Implications of optimising intakes of unsaturated fatty acids

6 Conclusions

Acknowledgements

References

Appendix 1

Summary Fat provides energy; indeed it is the most energy dense of all the macronutrients, with 1 g providing 37 kJ (9 kcal). However, the constituent parts of fat, fatty acids, are required by the body for many other functions than simply as an energy source, and there is an increasing awareness of the potential health benefits of specific types of fatty acids. Fatty acids are long hydrocarbon chains, with a methyl group at one end (the omega or n‐end) and an acid group at the other. Unsaturated fatty acids are hydrocarbon chains containing at least one carbon–carbon double bond; monounsaturated fatty acids contain one double bond, and polyunsaturated fatty acids (PUFAs) contain many double bonds. The position of the double bond relative to the omega end determines whether a PUFA is an n‐3 (omega 3) or an n‐6 (omega 6) fatty acid. Most fatty acids can be synthesised in the body, but humans lack the enzymes required to produce two fatty acids. These are called the essential fatty acids and must be acquired from the diet. In humans, the essential fatty acids are the n‐3 PUFA α‐linolenic acid and the n‐6 PUFA linoleic acid. Although humans can elongate dietary α‐linolenic acid to the long chain n‐3 PUFAs eicosapentaenoic acid and docosahexaenoic acid, the rate of synthesis may not be sufficient to meet requirements, and it is, therefore, recommended that good sources of these fatty acids, namely, oil‐rich fish, are also included in the diet. Fat is found in most food groups, and foods containing fat generally provide a range of different fatty acids, both saturated and unsaturated. In the UK, the major dietary sources of unsaturated fatty acids include meat & meat products, cereals & cereal products and potatoes & savoury snacks; primarily as a result of the vegetable oil used in processing. Recommended intakes of both total fat and the different types of fatty acids have been set for the UK population, and it is possible to monitor fat intake from the data collected in nationwide dietary surveys. As a population, we are not currently meeting these recommendations, so there is still scope for dietary change. In Western diets, n‐6 fatty acids are the predominant PUFAs, and this is in line with current dietary advice to consume a minimum of 1% energy as n‐6 PUFAs and 0.2% energy as n‐3 PUFAs. The balance of n‐3 and n‐6 PUFAs in Western diets has changed substantially over the last 100 years or so, and as the two families of PUFAs share a common metabolic pathway, concerns have been raised that this might be detrimental to health; what is becoming increasingly clear is that both n‐3 and n‐6 PUFAs have independent health effects in the body, and as intakes of the n‐6 PUFAs are within the guidelines for a healthy diet, concerns about the n‐6 to n‐3 ratio are driven by low intakes of n‐3 rather than high intakes of n‐6. Currently in adults n‐6 PUFAs contribute to 5.3% energy. Detecting associations between components of the diet and risk of various diseases is notoriously complex and in many cases, the evidence is still accumulating. Cardiovascular disease, characterised by hardening and narrowing of blood vessels and/or the development of blood clots, is one of the leading causes of mortality and morbidity worldwide. The type and total amount of dietary fat has a clear part to play in affecting an individual’s disease risk, yet the precise mechanisms by which unsaturated fatty acids reduce cardiovascular disease risk are still unclear. A number of mechanisms whereby dietary fatty acids could influence the progression of cardiovascular disease and its risk factors have been identified. These include effects on blood lipid concentrations, blood pressure, inflammatory response, arrhythmia and endothelial function, along with many other effects, both known and as yet undefined. A well‐established risk factor for cardiovascular disease is an elevated plasma low density lipoprotein (LDL) cholesterol concentration. Replacing saturated fatty acids with either monounsaturated fatty acids or n‐6 PUFAs reduces LDL (the ‘bad’) cholesterol, and so reduces the risk of developing the disease. Unsaturated fatty acids, such as linoleic acid or monounsaturated fatty acids, also slightly raise high density lipoprotein (HDL) (the ‘good’) cholesterol, which assists in the removal of triacylglycerols from the bloodstream. Interest in the health effects of the long chain n‐3 PUFAs found in fish oils is also increasing. There is strong supportive, but not yet conclusive, evidence that these fatty acids protect against fatal heart disease. On the basis of this conclusion, in 2004 the Scientific Advisory Committee on Nutrition advised the UK government to adopt the population‐wide dietary recommendation to eat at least two portions of fish per week, of which one should be oil‐rich, equivalent to 0.45 g of the long chain n‐3 PUFAs per day. In recent years, the potential health benefits of α‐linolenic acid has attracted attention, and evidence is mounting on the role that this n‐3 fatty acid may play in preventing the progression of cardiovascular disease, although it is currently unclear what, if any, association exists. Brain cells are especially rich in certain long chain PUFAs. This has led to the suggestion that dietary status of these long chain fatty acids might influence cognitive function and behaviour. Research in this field is still in its early stages, but there is a small amount of evidence to suggest improvements in cognitive function following fatty acid supplementation. In contrast, it is well established that pregnant women must have an adequate supply of the long chain n‐3 PUFAs before and throughout pregnancy and lactation to support normal growth, neurological development and cognitive function of the baby. As n‐6 PUFAs are more abundant in the diet, achieving an adequate intake is less problematic. However, this is not the case for the n‐3 PUFAs; increasing fish consumption beyond two servings of oil‐rich fish per week or relying on fish oil supplementation is not appropriate during pregnancy due to the potential problems associated with heavy metal contamination of fish, or the high vitamin A level in some fish oil supplements. Unsaturated fatty acids have also been associated with a number of other diseases and although the evidence is by no means conclusive, it is an area that is attracting a huge amount of interest. Dietary fat affects a number of different metabolic pathways, including those involved with glycaemic control, so the types and amounts of dietary fat may have a role to play in the management of type 2 diabetes. Unsaturated fatty acids may also be associated with a reduced risk of developing certain cancers, including cancers of the colon, breast and prostate, although currently the level of evidence is not deemed sufficient by authoritative bodies, such as the World Cancer Research Fund, World Health Organization and the Department of Health, to make any specific dietary recommendations. There are a number of inflammatory conditions, such as asthma, Crohn’s disease and arthritis, which could potentially be alleviated by dietary modification. The fatty acid composition of cell membranes can be altered by consumption of both n‐3 and n‐6 PUFAs, and this can result in reduced inflammatory activity. However, whether this effect brings about a significant reduction in clinical symptoms is still unclear. It is also important to note that there are concerns that the beneficial effects on certain disease outcomes are only observed with very high intakes of unsaturated fatty acids, which could realistically only be achievable by supplementation. Few nutritionists would be comfortable recommending supplement use as the only alternative to fish, as this can be expensive and goes against the idea that all the nutrients that our bodies require can be obtained from the food that we eat if the right choices are made. Unsaturated fatty acids are now a nutritional hot topic, and their presence in foods has attracted both public and industrial interest. There is currently no specific legislation to control the use of health claims relating to the fatty acid content of foods. However, a European Union (EU) Directive is expected imminently which will formally set down the criteria that a product will have to meet in order to make any nutrition or health claim. With regards to the current recommendations, those for the UK are in line with those around the world. However, as a population, we need to increase our consumption of long chain n‐3 PUFAs and decrease intake of saturated fatty acids. To facilitate this, food technologists are looking at ways in which the fatty acid profile of a food can be modified in order to bring dietary improvements without requiring a major change in dietary habits. However, public health messages surrounding the optimum intakes of fatty acids must be clear and consistent to ensure that a favourable change in the fatty acid profile of the UK diet occurs.     

Dietary fatty acid composition and metabolic syndrome in Tehranian adults

Objective

Several studies have shown that dietary and plasma fatty acid (FA) composition can modulate the development of metabolic syndrome, but epidemiologic data are scarce. The aim of this study was to evaluate the association between dietary FA composition and metabolic syndrome in Tehranian adults.

Methods

Dietary FA composition and symptoms of metabolic syndrome were assessed in a population-based cross-sectional study of 822 participants (354 men and 468 women, 18–74 y old) as part of the Tehran Lipid and Glucose Study. Metabolic syndrome was defined according to the guidelines presented by the Adult Treatment Panel III.

Results

The means ± standard deviations for dietary FA composition of total fat, linoleic acid, oleic acid, and saturated FA were 30.3 ± 7.5%, 1.43 ± 1.76%, 2.87 ± 2.19%, and 5.7 ± 2.2% of daily consumed energy, respectively. No significant correlation between the percentage of linoleic or oleic acids and metabolic syndrome was observed. Participants whose consumption of saturated FA was in the highest quartile had a significantly increased probability of acquiring metabolic syndrome (odds ratios by quartile 1, 0.83, 0.91, 0.95, P for trend <0.03). The odds ratios decreased after adjusting for indicators of a healthy lifestyle, including diet.

Conclusion

The data from this study indicate that increased consumption of dietary total fat, especially saturated FA, is associated with a higher risk of metabolic syndrome in Tehranian adults. The relation, apparently, is influenced by an individual’s lifestyle.     

孕期不同膳食模式对膳食脂肪酸含量及母初乳脂肪酸组成的影响

【目的】研究中国两种不同膳食模式地区膳食脂肪酸(fatty acid,FA)含量的差异,并探讨这种差异对母初乳脂肪酸组成的影响。【方法】对传统内陆膳食(常州)和海洋膳食(温州)地区孕晚期孕妇进行7d膳食调查,根据《2002中国食物成份数据》中的食物脂肪酸含量数据计算出膳食脂肪酸含量;并通过随访这些孕妇收集5d母初乳样本,采用高效毛细气相色谱分析技术检测5d母初乳的脂肪酸组成。【结果】常州与温州两地孕母摄入的膳食种类存在差异,温州地区孕母摄入的海洋食品远大于常州地区。常州地区孕母膳食脂肪酸中亚油酸(linoleic acid,LA)和α-亚麻酸(α-linolenic acid,ALA)含量均高于温州地区;而二十二碳六烯酸(docosahexaenoic acid,DHA)和二十碳五烯酸(eicosap-entaenoic acid,EPA)含量均低于温州地区;花生四稀酸(arachidonic acid,AA)含量则未见显著差异。两地膳食脂肪酸组成中LA、ALA、AA以及DHA的差异同样反应在5d母初乳中,但两地5d母初乳中的EPA含量差异无显著性。【结论】膳食模式不同的两个地区,其孕母的膳食脂肪酸含量存在差异,且这种差异可在母初乳脂肪酸组成中得到体现。     

染铅小鼠海马不饱和脂肪酸含量研究

目的 观察小鼠海马不饱和脂肪酸含量变化,分析其在铅致小鼠学习记忆能力受损可能机制中的作用.方法 48只ICR小鼠分为4组,分别饮用0.625、1.250、2.500 g/L醋酸铅溶液50 d,同时设立对照组(饮用去离子水),水迷宫法测定小鼠学习记忆能力后,颈椎脱臼处死,取海马,高效液相色谱法测定小鼠海马中油酸(C18:1)、亚油酸(C18:2)、亚麻酸(C18:3)、花生四烯酸(C20:4,AA)、二十碳五烯酸(C20:5,EPA)和二十二碳六烯酸(C22:6,DHA)等6种不饱和脂肪酸的含量.结果 (1)在训练的第1～4天,中、高染铅组小鼠逃避潜伏期均明显长于对照组,在训练的第4天,低染铅组小鼠逃避潜伏期亦明显延长,差异有统计学意义(P＜0.05);第1～4天的逃避潜伏期均与染铅剂量呈明显的正相关,r值分别为0.973,0.985,0.929,0.936.(2)中、高剂量组小鼠海马C18:2和从较对照组明显上升;而C18:3、EPA、DHA较对照组明显下降,差异均有统计学意义(P＜0.05);高剂量组小鼠海马C18:1含量减少,差异有统计学意义(P＜0.01).逃避潜伏期与C18:1、C18:3、EPA、DHA呈负相关,与C18:2、AA呈正相关,r值分别为-0.901,-0.914,-0.893,-0.855,0.936,0.727.结论 铅导致海马细胞脂肪酸代谢紊乱,使膜功能正常行使受阻,从而影响递质的合成、代谢和释放,导致学习记忆力的下降,推测这可能是铅干扰学习记忆能力的机制之一.     

Prolonged consumption of trans fat favors the development of orofacial dyskinesia and anxiety-like symptoms in older rats

Polyunsaturated fatty acids (FAs) are cell membrane components involved in brain functions. We hypothesized that long-term trans fat consumption is able to modify the membrane FAs composition impairing behavioral parameters related to aging. In this study, a comparison of behavioral parameters at 10 and 15 months of trans fat consumption by male Wistar rats was made. Animals were fed for 10 and 15 months from weaning with diets containing either 20% w/w soybean oil (SO), rich in n-6 PUFA, hydrogenated vegetable fat (HVF), rich in trans FAs, or a standard diet (control – C). At both evaluation times, HVF-fed rats showed progressively increased parameters of orofacial dyskinesia, fear and anxiety-like symptoms. The HVF diet reduced locomotor and exploratory activities progressively over 10 and 15 months of supplementation, while the standard and SO diets did not. In this study, we showed that chronic trans FAs consumption from weaning is able to favor the development of neuromotor and neuropsychiatric diseases, whose intensity was time dependent.     

Mercury exposure and omega-3 fatty acid intake in relation to renal function in the US population

It remains unclear whether exposure to low-level mercury (Hg) is associated with impaired renal function, and whether omega-3 fatty acid (FA) intake could affect the association of interest. The current study examined the association of blood Hg and omega-3 FAs with renal function using data from 1046 subjects aged 40 or above from the 2003–2004 National Health and Nutrition Examination Survey. Kidney function was assessed by estimated glomerular filtration rate (eGFR) and occurrence of albuminuria. Logistic regression analyses were applied to assess the association of interest with confounding variable adjustment. The analyses indicated that blood Hg was associated with reduced eGFR (<60 mL/min/1.73 m²) in a dose-response fashion (p < 0.05). The association was particularly apparent with adjustment for blood omega-3 FA levels. The adjusted odds ratio for having reduced eGFR was 2.94 (95% confidence interval = 1.04–8.33) in the highest tertile of blood Hg as compared with the lowest tertile. There was no significant association between Hg exposure and albuminuria. In summary, this study demonstrates that Hg exposure is associated with increased odds of having lower GFR in the US population aged 40 or above. A statistical association with albuminuria was not apparent. We also observed that omega-3 FA intake may play a preventive role in Hg-induced nephrotoxicity. Additional studies are warranted to determine the sources, exposure routes, and forms of Hg most responsible for observed associations.     

Association between dietary omega-3 fatty acid intake and depression in postmenopausal women

BACKGROUND/OBJECTIVESThis study aimed to analyze the association between dietary omega-3 fatty acid intake and depression in postmenopausal women using data from the Korea National Health and Nutrition Examination Survey (KNHANES) VI.SUBJECTS/METHODSThe KNHANES is a cross-sectional nationwide health and nutrition survey. Dietary data, including omega-3 fatty acids, were assessed using the 24-h recall method. Depression was evaluated using a survey questionnaire. The association between dietary omega-3 fatty acids and depression was evaluated using multivariate logistic regression analysis. Depression, according to the dietary omega-3 fatty acid intake, was expressed as the odds ratio (OR) with a 95% confidence interval (CI). A total of 4,150 postmenopausal women were included in the analysis.RESULTSIn the fully-adjusted model, the group with the highest dietary omega-3 fatty acid intake significantly showed lower prevalence of depression than the group with the lowest intake (OR, 0.52; 95% CI, 0.33–0.83); a significant linear trend was detected (P for trend = 0.04). According to the dose-response analysis using cubic restricted spline regression, this association was linear and monotonic (P for non-linearity = 0.32).CONCLUSIONSIn this study, the dietary omega-3 fatty acid intake in postmenopausal women was inversely proportional to depression in a dose-response manner. Large cohort studies are needed to verify the causality between omega-3 fatty acids and depression in Korean postmenopausal women.     

The quality properties and saturated and unsaturated fatty acid profiles of quail egg: the alterations of fatty acids with process effects

The nutritional composition (moisture, ash, crude protein, available carbohydrates, total lipids), energy value, some quality characteristics (yolk weight, albumen weight and shell weight), cholesterol level and fatty acid profiles of quail egg were determined (p<0.01). The protein content of quail egg was higher than laying hen's egg. The fatty acid composition of quail egg yolk consisted of 24 fatty acids including saturated fatty acids (C14:0, C16:0, C17:0, C18:0, C20:0, C22:0, C24:0), monounsaturated fatty acids (C15:1, C16:1, C17:1, C18:1n9, C18:1n7, C22:1n9, C24:1) and polyunsaturated fatty acids (C18:2n6t, C18:2n6c, C18:3n6, C18:3n3, C20:2, C20:3n6, C20:3n3, C20:4n6, C22:2, C20:5n3, C22:6n3). The total cholesterol level of quail egg was found to be 73.45±1.07 mg/100 g. Linoleic acid (C18:2n6c) (10.28%), arachidonic acid (C20:4n6) (1.92%) and cis-5,8,11,14,17-eicosapentaenoic acid (C20:5n3) (0.63%) were the major polyunsaturated fatty acids in the fatty acid content of quail egg yolk, whereas oleic acid (C18:1n9c) was the major monounsaturated fatty acid comprising 26.71% in the yolk. The palmitic acid (C16:0) and stearic acid (C18:0) levels were 16.62% and 6.89%, respectively. Total omega-3 was detected as 1.16% in raw egg whereas it was 0.82% in soft-boiled (rafadan) egg. The polyunsaturated fatty acid/saturated fatty acid proportion was 0.58 and 0.64 for raw and processed yolk, respectively.     

广州市居民含反式脂肪酸食物消费状况调查

目的了解广州市居民含反式脂肪酸（TFA）食物消费状况。方法采用多阶段分层整群抽样方法并考虑广州市区域发展水平差异,2011年抽取广州市越秀区、荔湾区、黄埔区、白云区、番禺区、花都区和南沙区进行调查。对每个区进行系统抽样抽取6个居委会,每个居委会随机抽取40户,凡抽中的住户≥3岁家庭成员均进行调查。采用自行设计的问卷,问卷调查内容包括调查户家庭基本情况、调查对象个人基本情况和个人过去3个月内含TFA食物消费的频率。调查户基本情况调查包括家庭经济收入、家庭人口数、民族等,调查对象基本情况调查包括年龄、性别、职业等。对调查结果进行描述性流行病学分析。结果本研究共调查5 244名≥3岁广州市居民,男、女性分别为2 565、2 679人,性别比为1∶0.96,3～、7～、13～、18～和≥50岁人群人数分别为931（占17.8%）、1 064（20.3%）、1 063（20.3%）、1 797（34.2%）、389（7.4%）人。文化程度以高中、中专以上为主,占60.1%（3 152/5 244）。2011年平均每月家庭年收入〈3 000、3 000～、5 000～和≥8 000元人数分别占22.5%（1 178/5 244）、22.0%（1 148/5 244）、19.9%（1 043/5 244）和32.5%（1 704/5 244）。广州市≥3岁居民含TFA食物平均消费量较高的分别为乳类、食用植物油、面包、糕点、冷冻饮品、生鲜肉及制品和油炸食品,依次为141.18、25.55、25.34、19.43、19.33、19.09和17.18 g/d。乳类、面包、糕点类、膨化食品、油炸食品、速冻食品、冷冻饮品、固体饮料、巧克力糖果类等食品在不同年龄组人群的平均消费量的差异均有统计学意义（P〈0.05或P〈0.01）,其中7～12、13～17岁人群在以上食品类别的平均消费量较高。乳类、面包、糕点类、油炸食品、速冻食品、冷冻饮品、固体饮料和巧克力糖果类不同收入水平居民含TFA食物的平均消费量差异均有统计学意义（P〈0.05或P〈0.01）,其中平均每月家庭纯收入≥8 000元的家庭以上食品类别的平均消费量较高。结论含TFA食物的消费量在广州市7～17岁学龄儿童和青少年人群中较高,有必要开展典型消费人群相关调查,为下一步开展风险评估提供参考。     

Variability in the trans fatty acid content of foods within a food category: implications for estimation of dietary trans fatty acid intakes.

OBJECTIVE: Currently, the published information on trans fatty acid composition of foods is incomplete and of questionable accuracy. Detailed fatty acid analysis of over 200 foods was undertaken for the purpose of determining the variability in trans fatty acid content among foods within a product category, and the significance of this variability to the estimation of trans fatty acids intakes from analysis of dietary intake data. METHODS: The analysis of food fatty acids used gas-liquid chromatography with 100 m capillary columns and standardized methodologies for food sampling, fat extraction, separation and quantification of trans fatty acid isomers. For the purposes of this report, trans refers to all non-naturally occurring isomers including trans, cis-trans, geometric and positional isomers. RESULTS: The results show that the amount of trans fatty acids varies considerably among foods within a category, reflecting differences in the fats and oils used in the manufacturing or preparation process. For example, the range of trans fatty acids in 17 brands of crackers was 23 to 51% total fatty acids, representing differences of from 1 to 13 g trans fatty acids per 100 g cracker. The large errors that may arise in estimates of the trans fatty acid intake of an individual are illustrated by analyses of the potential trans fatty acid intake in a sample diet, for each food as calculated using the minimum and maximum values for trans fatty acids within a given category. The results of these analyses show estimates of trans fatty acid intake from a low of 1.4 to 25.4 g a day for the same diet. CONCLUSION: This study shows that the wide variability in trans fatty acid content of different foods may result in large errors in the estimation of trans fatty acid intake of individuals and, potentially, groups.     

Detection of omega-3 fatty acid in designer eggs using hyperspectral imaging

Quantification of n-3 polyunsaturated fatty acids (PUFA) is an important aspect in quality control of designer eggs. Prediction of these fatty acids would be of value for egg grading stations. The aim of the present study was to evaluate the ability of hyperspectral imaging (HSI) to classify the eggs according their content in n-3 PUFA as a rapid and non-destructive technique. Furthermore, HSI was used to predict the content of n-3 PUFA in designer eggs. Normal eggs, eggs containing 75 mg and eggs containing 125 mg docosahexaenoic acid were purchased from a grocery store. After hyperspectral transmittance images were collected in the spectral region of 900–1,700 nm, the eggs were broken and analyzed chemically in order to measure fatty acid content. Regions of interest (ROIs) of about 3,000 pixels from each egg were selected. K-means analysis was performed to classify eggs into the three aforementioned types. The classification accuracy was 100%. A partial least-squares regression model was built and used to link the ROIs with results obtained from the chemical analysis. The correlation coefficients between the measured and predicted values of alpha-linolenic acid, eicosapentaenoic acid, and docosahexaenoic acid were 0.94, 0.73 and 0.87, respectively. The root mean square error values for the validation sets were 38.65, 3.31 and 7.03, respectively. These results showed that HSI could be used both for discriminating the eggs between normal and designer eggs and for prediction of n-3 PUFA content in eggs.     

德阳市市售植物油中反式脂肪酸含量调查

目的 了解德阳市市售植物油中反式脂肪酸的含量范围。方法 利用分层随机抽样抽取12类德阳市市售植物油共计121份样品,应用气相色谱法对样品中反式脂肪酸进行分离检测,采用归一化法进行结果计算。结果 德阳市市售植物油中12种反式脂肪酸的含量范围为未检出至3.19%,以反式亚麻酸（C18:3T）为主,其中橄榄油未检测出反式脂肪酸,最常见的菜籽油、玉米油、调和油、大豆油的反式脂肪酸平均含量分别为1.64%、2.20%、1.75%、2.58%。结论 德阳市市售植物油中普遍存在反式脂肪酸且含量各不相同。